After Ban Sheng finished saying those words, he pulled back and turned to walk in the opposite direction. He turned sideways to push open the rolling shutter door, and with a thunderous boom, a vast rush of air flooded in.

After he left, someone turned on the lights — no one knew who. With a sharp click, the overhead fluorescent lights blazed on, bright as midday, so dazzling that Lin Weixia instinctively raised her hand to shield her eyes.

When they returned, Qiu Yan had almost finished eating. Lin Weixia took the bill to the front counter to pay. As the two of them pushed open the door and stepped outside, Qiu Yan suddenly seemed to remember something and said:

“Oh, right — Ban Sheng sent me a message saying he had something to take care of and left early.”

“Mm.” Lin Weixia replied.

After that, Lin Weixia never attended another gathering. The phone number saved in her contacts was never pulled up again.

She returned to her solitary routine — back and forth between school and the apartment, nothing more.

Tuesday. Heavy snow. Lin Weixia hugged her textbooks and walked into school. The snow that day fell thick and deep; workers were out shoveling the paths. A few white doves that hadn’t flown south were sheltering beneath the great bell tower on campus. Lin Weixia was in the middle of a discussion with a classmate when, without thinking, she caught a glimpse of a familiar silhouette.

Ban Sheng was walking and laughing with a group of young men and women, some tattooed with full sleeve artwork, others with lip piercings. The weather was bitterly cold, yet he wore only a grey hooded sweatshirt, his pale skin flushed with reddish capillaries from the cold, hood pulled up over his head.

It was daytime, and without his outdoor jacket on, Lin Weixia finally noticed a tattoo at Ban Sheng’s collarbone.

A new tattoo, though she couldn’t make out what it was.

The tattoo was half-hidden beneath the neckline of his collar, like some incomplete creature serpentine along his collarbone.

Someone nearby must have said something funny — he laughed with careless ease, reaching out to flick off cigarette ash. But the smile never reached his eyes.

Time truly has a way of changing people.

The Ban Sheng of before wore a cool, aloof expression and always drifted apart from the crowd, never mixing with anyone. Now he seemed to have willingly let go of himself, dragging himself downward.

Lin Weixia pulled her gaze away from him and continued walking forward with her classmate. As their two groups passed each other, one of the boys in Ban Sheng’s group was so engrossed in talking to his companion that he bumped into Lin Weixia, sending the books she was carrying tumbling to the ground.

He apologized repeatedly and crouched down to help her collect them; his companion stopped to wait. Lin Weixia said softly that it was fine.

He handed the collected books back to her. Lin Weixia took them and brushed off the snowflakes, and in doing so, her gaze accidentally met Ban Sheng’s eyes through the crowd.

He gave her a slight nod of his chin — a greeting of sorts.

And then they walked on.

Ban Sheng’s greeting was neither warm nor cold. He didn’t go out of his way to be friendly, but neither did he loathe her enough to pretend she was invisible.

He treated her the way one treats a friend of a friend. Nothing more.

And somehow, that hurt even more.

For a brief moment, Lin Weixia’s nose stung — sharp enough that her eyes began to prick. Her classmates noticed nothing unusual, and one of them murmured admiringly, “That Chinese boy who just passed by was really handsome.”

“I remember him — he’s quite brilliant academically. Isn’t he in the Biomedical Engineering department?”

“What? Isn’t he in the Astronomy program?” Lin Weixia’s expression shifted with confusion. She suspected she had misheard.

Her companion tapped the side of her head and murmured, half to herself, “No, I’m pretty sure he’s in Biomedical Engineering. I remember he was especially outstanding in Physics and Computer Science — that’s probably the path he wants to take.”

Lin Weixia was distracted for the entire class that followed. She kept thinking: back at Shengao, everyone knew Ban Sheng had ranked first in Physics. What he most wanted to study was Astrophysics. His dream was to work for NASA one day.

The Ban Sheng who had broken his leg climbing alone into the northwest mountains just to photograph a single image. The boy whose room was covered wall to wall in posters of nebulae. The boy who had worked through all of the high school Physics curriculum by his first year of senior high school. The boy who, mid-conversation, would start calculating galactic coordinates in his head. Why had he not chosen the Astronomy program he loved? Why Engineering instead?

She didn’t know.

Back at the apartment, Lin Weixia stood in the entryway taking off her shoes, when Shengxia wagged its tail over and snatched her white socks in its mouth, then bolted off in gleeful chaos.

Lin Weixia changed into her cotton slippers, retrieved her laptop from her room, and settled onto the sofa — one long leg bent up on the cushion, the other resting on the hardwood floor.

She logged into the University of Pennsylvania’s official website and typed in Ban Sheng’s name. A loading circle spun slowly on screen. Her heart was restless. After a moment, Ban Sheng’s personal profile page appeared.

The same cold, imperious face. No expression whatsoever looking into the camera.

The page clearly displayed the year 20XX — Biomedical Engineering, Class One. Ban Sheng. She scrolled down; it was only basic personal information.

Lin Weixia felt completely stunned.

Qiu Yan was sitting cross-legged on the living room rug, playing her Switch. Lin Weixia tried to speak but found her throat too dry; she swallowed involuntarily:

“Qiu Yan — has Ban Sheng always been in Biomedical Engineering?”

“Of course, didn’t you know? He’s an engineering prodigy. He gets an A in everything, excels at whatever he tries, wins every competition he enters. Though what a shame — he’s about to go back to China…” Qiu Yan’s eyes lit up at the mere mention of Ban Sheng’s name.

Lin Weixia’s ears started ringing again. All manner of noise surged in, making it impossible to think. She asked, “Go back to China?”

“You didn’t know? Ban finished his credits early specifically so he could go home — even his advisor here couldn’t talk him out of it. His flight is tomorrow…”

Whatever Qiu Yan said after that, Lin Weixia could no longer make out. She could only watch Qiu Yan’s lips moving, opening and closing. She typed a message to senior Wusuan, her fingers trembling slightly:

[Senior, do you know why Ban Sheng changed his major?]

Her phone screen lit up almost immediately. Wusuan replied, choosing her words carefully:

[I honestly don’t know either. He never told us about that. Go ask Ah-Sheng yourself — he’ll tell you.]

Lin Weixia lowered her gaze and typed back in the chat window: [Alright. Thank you, senior.]

The next day. Overcast and rainy. No classes all morning. Lin Weixia lay in bed — she had barely slept the whole night, tossing and turning with everything Qiu Yan had told her cycling through her mind.

Biomedical Engineering.

Going back to China.

Changed majors.

What had happened to Ban Sheng after the university entrance exams, she had no way of knowing. She only hoped he could freely chase his own dreams.

Thinking this, Lin Weixia pulled out her phone from under the pillow, opened her contacts, found his number, and after a moment’s hesitation, pressed call.

The phone rang with cold, hollow tones — beep, beep, beep — and Lin Weixia’s heart stayed suspended throughout. After a long while, a gentle woman’s voice came from the other end: “I’m sorry, the number you have dialed is temporarily unavailable. Please try again later…”

The hand holding the phone sank down, powerless.

He was probably already on the plane by now. Fate loved to play these tricks. She had traveled halfway across the world to follow him here, and he had gone back.

Lin Weixia remained on the American side, studying alone through the final month, then finally flew home.

When she landed at the Jingbei airport, Lin Weixia pushed her luggage cart out through the security exit. Among the crowd waiting to receive arrivals, she spotted Menzi at once.

Menzi was dressed to turn heads that day — black jacket over a figure-hugging pencil skirt, tall boots encasing two chopstick-thin long legs, and dark sunglasses perched on her face despite the late hour, her striking face utterly expressionless.

The way she carried herself was practically celebrity-level; it actually attracted a passerby who tried to sneak photos of her, earning a sharp, impatient glance from Menzi.

Lin Weixia watched all of this and, finally recognizing her, smiled. She walked up and tugged playfully at a streaked curl of Menzi’s long hair:

“You dyed your hair? It looks nice.”

Menzi took her luggage and replied, “Don’t even get me started — I just went through a breakup. New hair, new energy, out with the bad luck.”

After they left the airport, Menzi drove Lin Weixia home. Knowing she’d been exhausted by the long journey and needed rest, Menzi didn’t linger — she ordered Lin Weixia a food delivery and left.

The apartment Lin Weixia was renting was a small one-bedroom-one-living-room unit, and things were piled everywhere. By the time she’d tidied up, it was past midnight. Lin Weixia let herself fall sprawling onto the bed, the mattress bouncing with a muffled thud.

She was too exhausted to think. Soon, she drifted into a fuzzy, fitful sleep. In the dream, Ban Sheng’s eyes were reddened at the corners, his gaze fixed and pressing on her, suffocating as he said —

Lin Weixia, you have no heart.

She woke in a cold sweat. Fortunately, she only had one class, and it didn’t start until 10:20 in the morning. Lin Weixia walked to the bathroom, squeezed out some mint toothpaste, and brushed her teeth while boiling water.

After setting out food and water for the dog, she tucked her books under her arm and headed off to class.

The class was Cognitive Psychology. Partway through, there was a ten-minute break. Lin Weixia sat on her desk sorting through her notes while her classmates turned to chat with each other.

One girl said, “Hey, did you hear? Someone from UPenn came to the Engineering building as an exchange student — his name is Ban Sheng or something! Apparently he’s some kind of genius, and drop-dead gorgeous, too — they say he’s already enchanted a whole crowd of girls. We should crash one of his classes one day; I have to see for myself how good-looking he is.”

A male classmate chimed in, “I heard about him. His black GTR is even more impressive — I heard he actually drove it onto campus once. I walked past and took a photo.”

“You guys — cars and sneakers, that’s all you ever care about. Can’t you have any other interests?” the girl shot back.

Lin Weixia’s lashes flickered slightly; she continued looking down to sort her notes, not joining the conversation. But some of the words slipped into her ears anyway:

“Though for a genius, his lifestyle is pretty out of control. I heard that apart from showing up to class, you basically never see him on campus otherwise. Apparently he spends his time at places like bars or doing street racing — and from what I’ve heard, things get pretty wild. So much for being a genius.”

“Apparently he won over the art department’s goddess within two days — that Shi Li, the one who’s notoriously difficult to approach. I’ve never seen her look at a guy twice before…”

A black fountain pen had been copying notes onto a vintage-green notebook. When it reached the words “when cognition encounters obstacles,” the pen nib paused heavily, and a dark blot of ink bloomed and spread rapidly across the page.

The class bell rang shortly after. Those who’d been gossiping scattered like startled birds, and the classroom settled back into its usual quiet, focused atmosphere.

After class, Lin Weixia capped her fountain pen, tucked her books under her arm, and walked out of the tiered lecture hall. The moment she reached the bottom of the stairs, she spotted Menzi standing at a distance under a sycamore tree, waiting for her with a camera bag on her back.

“What do you want for lunch?” Lin Weixia asked, walking over.

“Beef braised noodles? Pan-fried rice cakes? Or rice?” Menzi replied.

The two girls chatted as they made their way toward the cafeteria. It was peak lunch hour, and the ground floor was packed. Menzi, unwilling to queue, grabbed Lin Weixia’s arm and pulled her upstairs to the second-floor dining room.

They both ordered pan-fried rice cakes. As soon as they sat down, Menzi pointed toward the cold drinks counter nearby and said, “Salty lemon soda — isn’t that from your side of the country, down in Nanjiang?”

Lin Weixia paused. Her long lashes swept down, veiling the ripple in her eyes:

“I haven’t had that in many years.”

The two ate together. Lin Weixia picked up a piece of rice cake with her chopsticks, put it in her mouth, and then seemed to think of something. She asked Menzi: “If you hurt someone in the past, and now that person isn’t doing well — what would you do?”

“Your question is too broad. First, you’d need to determine whether that person ended up this way because you hurt them, or because of their own circumstances.”

“And second, what is this person to you? A friend? A former lover? The nature of the relationship changes what you’d do. Most importantly, you need to ask yourself what’s in your own heart.” Menzi usually came across as scatterbrained, but the words she spoke cut straight to the heart of things.

Lin Weixia had eaten about half her beef noodles when she received a message from her professor mid-meal, asking her to come to the laboratory building at two o’clock that afternoon to collect some materials.

At two in the afternoon, Lin Weixia parted from Menzi and went to the second floor of the laboratory building, where she found Professor Liu’s office and collected a stack of documents.

She glanced at the materials and decided to find a quiet corner on the rooftop to read by herself. Lin Weixia climbed staircase after staircase, passing classrooms where lab sessions were in progress, the tightly shut doors occasionally letting out the low murmur of students speaking.

By the time she reached the rooftop on the sixth floor, her lips were slightly parted, and she had one hand braced against the wall, catching her breath. She looked up at the door in front of her — it was half-open.

Lin Weixia stepped out. Cold wind swept over her. The sky was a blurry grey-white. She suddenly heard a soft, muffled cry from a girl, followed by a man’s low laugh.

The man’s voice carried a cool edge. It was vaguely familiar.

Near the stairwell entrance on the rooftop stood a small storage shed crammed with discarded equipment. The sounds were coming from the open ground in front of the shed.

She couldn’t see anyone.

Lin Weixia moved closer. She pressed her back against the wall, but didn’t dare step around the corner — her heart felt as if a sharp rope were winding and rewinding around it, squeezing tight. What was she afraid of?

She was afraid it was him.

Afraid of seeing him there.

Lin Weixia leaned against the wall, tilted her body forward, and stole a cautious glance. A young man was holding a girl close, his back to Lin Weixia, his neck bent as he was intimate with her.

The man wore a black jacket. He was roughly 185 centimetres tall, with a build that very much resembled him — but she couldn’t see his face.

Lin Weixia stood there in quiet torment, her palm pressed against the grey concrete wall. A small pebble came loose under her fingers, rolling soundlessly across the ground.

She needed to be sure. Just as she was about to step around to look, a cold, powerfully aggressive presence hit her as a hand seized her snow-white wrist.

Before she could react, the storage shed door near the stairwell was wrenched open, and Lin Weixia was shoved inside. Darkness surrounded her; startled, she let out a cry, and the other person swiftly clapped a hand over her mouth.

Lin Weixia’s eyes flew open. The mottled, faint light carved out a face with sharp, distinct features. Her gaze drifted down to the small mole beneath his eye.

She exhaled in relief.

It was Ban Sheng.

But the commotion as they entered was not quiet, and the man outside called out: “Who’s there?”

Silence answered the couple outside.

“Probably some stray cat,” the girl said.

They stood still in the cramped space. Since their reunion, this was the closest the two of them had been to each other. Ban Sheng’s hand covered Lin Weixia’s mouth — his palm broad and slender-fingered, its heat running into her, scorching her face with a dense, spreading warmth.

Their breathing intertwined — one hurried, one slow.

A faint, ambiguous tenderness began to kindle.

“Forget it, let’s go,” the girl said.

Ban Sheng released his hand accordingly. After the unfamiliar couple departed, the air fell quiet, leaving only the song of a skylark.

He turned, pulled open the door, and bright light poured in. Ban Sheng bent down slightly, about to leave — when Lin Weixia fixed her eyes on that casually departing figure and called out to him. The moment her voice emerged, it trembled without her meaning it to:

“Ban Sheng — why did you change your major? Why didn’t you study Astronomy?”

The tall young man’s frame went still. He leaned against the doorway, toying with the lighter in his hand, and glanced back at Lin Weixia with a languid, offhand air:

“Want to know? Come find me at TAK bar this Sunday night at eight o’clock.”